Will vegetarian marshmallows set a Grasshopper Pie or do you need the gelatine in regular marshmallows?
Nigella's Grasshopper Pie (from KITCHEN) has a chocolate crust that has a mint flavoured mousse-like filling. The filling is made with melted marshmallows and whipped cream and the gelatine in the marshmallows helps to set the filling. The marshmallows need to be melted at a very low temperature so that the mixture will set, as gelatine will lose its setting qualities if boiled.
Vegetarian marshmallows are often made with carrageenan, which is derived from seaweed. Unfortunately carrageenan needs to be treated differently to gelatine as it needs to be brought to a high temperature to activate its gelling properties. In addition, carrageenan can set more firmly in dairy dishes as it reacts with calcium to produce a stronger gel. So the method and quantities of the recipe may need to be adjusted and unfortunately we are unable to advise on this. It may be possible to set the Grasshopper Pie filling by using a vegetarian alternative such as agar agar or carrageenan instead of marshmallows, but unfortunately we have not tested the recipe using these and regret that we are unable to advise on the quantities needed.